From 8b1efc53ca99361837a8da7580e960de645db51a Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Thu, 21 Nov 2019 11:56:46 +0100
Subject: [PATCH] Make Optional readonly.

---
 src/Avalonia.Base/Data/Optional.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Base/Data/Optional.cs b/src/Avalonia.Base/Data/Optional.cs
index de7d6a307d..80abd90646 100644
--- a/src/Avalonia.Base/Data/Optional.cs
+++ b/src/Avalonia.Base/Data/Optional.cs
@@ -20,7 +20,7 @@ namespace Avalonia.Data
     ///   conversion from <typeparamref name="T"/>
     /// - For an missing value, use <see cref="Empty"/> or simply `default`
     /// </remarks>
-    public struct Optional<T>
+    public readonly struct Optional<T>
     {
         private readonly T _value;